1. Field of the Invention
The present invention relates to an image display apparatus and an image display method for displaying a different image superimposed over a background image, such as a moving picture.
2. Description of the Related Art
Display apparatuses including television receivers that display a child picture superimposed on part of a parent picture have been known (refer to, for example, Japanese Unexamined Patent Application Publication No. 2003-101462, in particular, pages 3 to 5 and FIGS. 1 to 9). In such display apparatuses, a parent picture is the background image and a child picture is displayed on a fixed region of the parent picture.
In the display apparatus disclosed in Japanese Unexamined Patent Application Publication No. 2003-101462, a child picture is displayed over the fixed region of the parent picture. Consequently, the image of the parent picture to be displayed in this region is hidden, and therefore, the visibility of the background image (i.e., the parent picture) is deteriorated. This problem occurs when a moving image and the like is displayed as a background image and when a different image, such as emergency information, is displayed on a part of the background image. Accordingly, this problem is inevitable as long as a different image is displayed without considering the content of the background image.